Rubber blanket and device for fixing a rubber blanket

ABSTRACT

A rubber blanket is provided with reinforcement rails on one or both of its ends. These reinforcement rails are positionable in a narrow channel in a rubber blanket cylinder. The reinforcement rail or rails extend beyond the ends of the channel. Rubber blanket cylinder tensioning devices engage the extending ends of the rubber blanket reinforcement parts.

FIELD OF THE INVENTION

The present invention relates to a rubber blanket and to a device forfastening a rubber blanket on a rubber blanket cylinder of a rotaryprinting press. The blanket has at least one reinforcement rail at oneof its ends. This reinforcement rail extends beyond the width of theblanket and is useable to secure the blanket to a cylinder.

DESCRIPTION OF THE PRIOR ART

A rubber blanket tensing device is known from DE 196 16 337 A1. Each endof the rubber blanket is provided with a suspension rail. Here, a first,or leading, end is brought into a lateral cutout of the cylinderchannel, and a second, or trailing, end is radially pulled into thechannel by a tensing strip and is tensed in this way.

DE 78 20 773 U1 discloses a rubber blanket with suspension rails. Thesuspension rails protrude past the width of the rubber blanket.

SUMMARY OF THE INVENTION

The object of the present invention is directed to providing a rubberblanket and a device for fastening a rubber blanket.

In accordance with the present invention, this object is attained byproviding the rubber blanket with at least one reinforcement rail at oneend. Both blanket ends can have reinforcement rails. These reinforcementrails may have a height that is at least twenty times the thickness ofthe blanket. The rail or rails have a length greater than the width ofthe blanket. This length extends past the width of the blanket. Theprotrusion works with a blanket fastening device.

The advantages which can be achieved by the present invention reside, inparticular, in that only a narrow visible tensioning or securementchannel is provided, so that a large printing length can be achievedwith the rubber blanket cylinder. Neither a tensioning spindle nor atensioning strip are required for this simply and dependably operatingdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention is represented in thedrawings and will be described in greater detail in what follows.

Shown are in:

FIG. 1, a partial cross section view through a cylinder with the deviceof the invention and taken along the section line I—I of FIG. 2, and in

FIG. 2, a top plan view on the end of a cylinder with the devicecorresponding to the representation in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A rubber blanket 03, for example of a thickness “a” of approximately 2mm and a width “b” of approximately 1000 mm, rests on the surface 01 ofa rubber blanket cylinder 02. A first—for example U-shaped—reinforcementrail 07 and a second reinforcement rail 08 are interlockingly attachedto or incorporated into the material of the rubber blanket 03 at thefirst and second ends 04, 06, respectively of the rubber blanket 03.They are sufficiently bending-resistant in respect to their longitudinalaxis. Cross-sectional, form and section modulus have been appropriatelyselected. On the left and on the right ends of the rubber blanket 03,the reinforcement rails 07, 08 each protrude with their first or leftends 12 and their second or right ends 13 laterally past the rubberblanket 03 by at least five millimeters, as seen in FIG. 2. Thereinforcement rails 07, 08 are longer than the rubber blanket 03 iswide.

As stated, the first and second ends 04, 06 of the rubber blanket 03 arefastened to the reinforcement rails 07, 08, for example by rivets, or bygluing, vulcanizing, etc. The reinforcement rails 07, 08 can each have aheight “f”, which height “f” is twenty to forty times the thickness “a”of the rubber blanket 03.

The ends 12, 13 of the reinforcement rails 07, 08, whose edges have beeninserted into a cylinder channel 14 formed in the blanket cylinder 02,protrude past the width “b” of the rubber blanket 03, as well aslaterally out of the cylinder channel 14, again as seen in FIG. 2.

The ends 04, 06 of the rubber blanket 03, with the part of thereinforcement rails 07, 08 fastened on them, are inserted into thenarrow cylinder channel 14, which extends in approximately the radialand axial direction of the rubber blanket cylinder 02. The opening 16 ofthe channel 14 facing toward the surface 01 of the blanket cylinder 02is in the form of a gap having an inside width “g”. The cylinder channel14 has been widened trapezoidally in cross section to an inside width“h”. A trapezoidal cross-sectional shape of the cylinder channel 14 isadvantageous because it is possible, in this way, to position thereinforcement rails 07, 08 away from each other in the interior of thecylinder channel 14.

The width “g” of the surface opening 16 of the channel 14 can be keptvery narrow. It approximately corresponds to the thickness “a” of therubber blanket 03, plus the thickness “c” of a reinforcement rail 07,plus a small added amount.

The cylinder channel 14 can be longitudinally divided into twocompartments 19, 21 by a guide strip 18, as represented in dashed linesin FIG. 1, which guide strip 18 is fastened on the channel bottom 17,extends upward and is wedge-shaped. Because of this guide strip 18, itbecomes possible for each end 04, 06 of the rubber blanket 03 to beguided into its own compartment 19, 21. In the course of this, thereinforcement rails 07, 08 are conducted away from each other.

A device 20 for generating a pressure force on the free ends 12 and 13of the reinforcement rails 07, 08 is provided to the left and right onthe blanket cylinder 02 next to the start and end of the cylinderchannel 14. Device 20 is situated, with respect to the free ends of thereinforcement rails 07, 08 directly next to them or distanced from them.The device 20 is supported on the rubber blanket cylinder body andgenerates a pressure force on the free ends 12 and 13 of thereinforcement rails 07, 08 acting in the radial direction; i.e. in thedirection toward the axis of rotation of the rubber blanket cylinder 02and in this way holds and tensions the rubber blanket 03.

Devices 20 for generating a pressure force are provided for each freeend 12, 13 of the reinforcement rails 07, 08. They comprise, forexample, respective tensioning blocks 24, 26, each of which can be movedin the direction toward or away from the axis of rotation of thecylinder, or radially up and down, by a releasable interlockingconnection, for example respective screws 27, 28, at the side of thecylinder channel 14 of the rubber blanket cylinder 02, and in this waycan exert pressure force on the free ends 12, 13 of the reinforcementrails 07, 08.

Each tensioning block 24,26 fixed against relative rotation, and forexample each has a projection 29 extending around and resting againstthe free ends 12, 13 of the reinforcement rails 07, or 08, as shown mostclearly in FIG. 1.

In the radial direction of the blanket cylinder 02, the tensioningblocks 24, 26 also have distances of different length from the surface01 of the rubber blanket cylinder 02, as seen in FIG. 1. Thus, bothtensioning blocks 24 of the first or leading end 04 of the rubberblanket 03 are farther distanced from the surface 01 than the tensioningblocks 26 of the second or trailing end 06 of the rubber blanket 03.

The devices 20 are each fastened in a cutout 23 on the barrel of therubber blanket cylinder 02. One wall of this cutout 23 can be used as atorsion guard. However, the devices 20 can also be fastened on bothfront faces 22 of the rubber blanket barrels.

While a preferred embodiment of a rubber blanket and of a device forfixing a rubber blanket to a blanket cylinder in accordance with thepresent invention have been set forth fully and completely hereinabove,it will be apparent to one of skill in the art that various changes in,for example, the overall size of the cylinder, the drive for thecylinder and the like could be made without departing from the truespirit and scope of the present invention which is accordingly to belimited only by the following claims.

What is claimed is:
 1. A rubber blanket comprising: a first blanket endand a second blanket end; a first reinforcement rail on said firstblanket end and a second reinforcement rail on said second blanket end,said first reinforcement rail having a first length and said secondreinforcement rail having a second length, said first and second lengthsbeing different from each other; a width defined by each of said firstblanket end and said second blanket end, said first and second lengthsboth being greater than said width, said first and said secondreinforcement rails protruding beyond the rubber blanket at differentlengths.
 2. The rubber blanket of claim 1 wherein each of said first andsecond reinforcement rails protrude past said rubber blanket by at leastfive millimeters.
 3. A device adapted to fasten a rubber blanket to arubber blanket cylinder comprising: a first reinforcement rail on atleast one end of the rubber blanket, at least a first end of said firstreinforcement rail extending beyond a width of the rubber blanket;reinforcement rail end engagement devices on the blanket cylinder; acylinder channel in said rubber blanket cylinder and having a channelbottom; and a strip of wedge-shaped cross-section in said cylinderchannel and secured to said cylinder bottom.
 4. The device of claim 3wherein said device includes a tensioning block movably supported onsaid rubber blanket cylinder by screws.
 5. The device of claim 3 whereinsaid cylinder channel in said rubber blanket cylinder is trapezoidallyshaped, said cylinder channel widening toward a radially inwardlylocated channel bottom.
 6. The device of claim 3 further including firstand second ends of said first reinforcement rail, and a separate one ofsaid reinforcement rail end engagement devices for each of said firstand second ends of said first reinforcement rail.
 7. The device of claim3 further including a second reinforcement rail on a second end of therubber blanket and further including separate ones of said reinforcementrail end engagement devices for each of said first and secondreinforcement rails.
 8. The device of claim 7 wherein said firstreinforcement rail end engagement device and said second reinforcementrail end engagement device are axially offset on said rubber blanketcylinder with respect to each other.
 9. The device of claim 7 whereinsaid first reinforcement rail end engagement device and said secondreinforcement rail end engagement device are radially circumferentiallyoffset on said rubber blanket cylinder with support to each other.
 10. Adevice adapted to fasten a rubber blanket to a rubber blanket cylindercomprising: a first reinforcement rail on at least one end of the rubberblanket, at least a first end of said first reinforcement rail extendingbeyond a width of rubber blanket; and reinforcement rail end engagementdevices on the blanket cylinder, each of said reinforcement rail endengagement devices including a tensioning block movably supported onsaid rubber blanket cylinder by screws, each said tensioning blockhaving a torsion guard.
 11. A device adapted to fasten a rubber blanketto a rubber blanket cylinder comprising: a first reinforcement rail on afirst end of the rubber blanket, at least a first end of said firstreinforcement rail extending beyond a width of the rubber blanket; asecond reinforcement rail on a second end of the rubber blanket; a firstreinforcement rail end engagement device for said first reinforcementrail on said rubber blanket cylinder; and a second reinforcement railend engagement device for said second reinforcement rail on said rubberblanket cylinder, said first and second reinforcement rail endengagement devices being axially offset on said rubber blanket cylinderwith respect to each other.